Poison Ivy, Oak and Sumac

                                              by Deborah Koziara RN, CS-FNP

 The following are some tips on the recognition, signs and symptoms, treatment and prevention of allergic contact dermatitis caused by poison ivy, oak and sumac.

 Definition:

    Rhus plants (poison ivy, poison oak and poison sumac) are the most common cause of allergic contact dermatitis in the United States.  The rash from poison ivy, oak or sumac is caused by contact with oils found in their sap. The oil, urushiol, is found in their roots, stems, leaves and fruit and is poisonous at all times of the year, even when the plant is dead.  The sensitivity to urushiol can develop at any time and the more often you have contact with it, the more likely you are to develop an allergic rash.  Exposure can occur in three ways: 1.) direct contact-touching the sap of the plant 2.) indirect contact-touching something that has the oil on it (eg. animal fur, garden tools, clothing, shoes, or sports equipment and 3.) airborne-oil particles in the air (eg. from burning the plants, lawnmower or trimmer).

Recognition:          

     Poison ivy leaves consist of three pointed leaflets, with the middle leaflet having a much longer stalk than the two on the side.  The leaflet edges can be smooth or toothed.  The leaves range in size from less than ½ inch to 2 1/4 inches in length.  They are reddish when they emerge in the spring, turn green during the summer and become various shades of yellow, orange or red in the fall.   The plant has small greenish flowers which grow in bunches attached to the main stem and later in the season has white, wax-like berries which form.

     Poison ivy grows as a vine or woody shrub with hairy roots and it may grow to 10 feet or more, climbing up trees, walls or fences or as trails along the ground.  It is found in every region of the United States except the Southwest, Alaska and Hawaii. 

     Poison oak may grow as a vine but is usually a shrub.  It is found primarily on the west coast.  It has three leaves that are shaped somewhat like oak leaves.  The underside of the leaves are a much lighter green than the surface and are covered with hair.  It may develop clusters of green or creamy white berries. 

     Poison sumac grows as a shrub, especially in swampy locations.   Each stem contains 7-13 leaves arranged in pairs with a single leaflet at the end.  It grows 5-6 feet high with elongated leaves without teeth.

Signs and Symptoms: 

     The itchy rash of poison ivy typically appears within 1-3 days after exposure to the urushiol, but may appear as long as 2-3 weeks after exposure.  

     Redness and extreme itching, often accompanied by swelling, are the first signs followed by a pimply red, rash which later blisters.  

     The blisters break within several days, followed by crusting and then disappear.  

     The worst stage of the rash is on days 4-7 after exposure to the urushiol oil.  The rash may last for 1-2 weeks and reactions vary from very mild in some individuals to very severe in extremely sensitive individuals. 

Treatment:                   

      If you are exposed to poison ivy, oak or sumac the first and most important step in preventing the rash is to wash with soap and water within 5-10 minutes of exposure.  After 10 minutes the oils will have penetrated the skin and can’t be washed off.  If all the oils can be washed off within 5-10 minutes there should be no reaction. 

     Scrub under the fingernails with a brush, if available, to remove all the oil and prevent spreading to other parts of the body. 

     Wash all clothing and shoes of the exposed person as soon as possible with soap and water.  

     Also, wash any sporting, gardening, hunting, fishing or camping equipment that may have touched the oil.

     Urushiol can remain active on any surface from 1-5 years.

     Bathe all animals that may have been exposed as they can carry the oil on their fur.

     Cool compresses of water or dilute aluminum acetate (Burrow’s solution) may relieve inflammation.  Cool showers or warm baths with oatmeal or baking soda solution may also relieve itching and promote drying of blisters.

     Apply over the counter lotions and creams, such as calamine lotion or 1% hydrocortisone cream to decrease itching.

     Do not scratch blisters as it may lead to secondary infection.
Scratching or oozing blister fluid cannot spread the rash.

     Call the doctor if the rash is severe.

Avoidance:                        

   Learn to recognize and avoid these plants.   

   Remove the plants if growing near your home.  Never burn the plants!

   Wear long sleeves, long pants, and socks in heavily wooded areas.

   Bathe the family pet if there is a chance that he/she has had contact with the plants.

   Avoid handling objects which may have touched the plants and if you do touch them wash with soap and water right away.

   Try over the counter products such as Ivy Block that contains bentoquatam and can protect for up to 4 hours.  

Poison Ivy Links                 

Poison Ivy Web Site  

Poison Ivy, Oak and Sumac Information Center

      Many pictures used on this page are from www.poison-ivy.org

    This page was used with the permission of:

Marilyn Bishop, RN, MSN
Special Projects Nurse
Fuller Middle School
31 Flagg Drive
Framingham, MA 01702

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